Core for reinforced concrete or plaster floor construction.



c z.l F. HENNms. CURE F08 REINFORCED CONCRETE 0R PLASTER FLUOBGQNSTRUCTVION.l

APPLICATIUI FILID IULY 28| 1915.

1,918,999. 1mm-uu. 13, 1917,.

plete core re'ady with a top 2 and sies 4 which the follown ble, a`great vention will be` pmianns ir.

ensuit wml?, Ol' CHICAGO, ILLINOIS, C0 ANY, 0F CHICAGO, ILLINOIS, A

ASSIGNOR T0 STATES CORPORATION OF NEW JERSEY.

CORR FOB BEINFOBCED CONCRETE 0B PLABTER `I-E'LOOB. COINBlBlJ'C'JION.`

speeltuinen' er Letten raamt Original application illed April 9, 1915,loria] No. 20,162. Divided and this application illed J'nly 88, 1915.

Serial No. 41,887. i

To all'whomt may concern:v

Be it known that I, CHARLES F. HENNING, a citizen of the United States,residinsg at Chica in the county of Cook and tate of Illinois, haveinvented certain new and useful Improvements in Cores for ReinforcedConcrete or PlasterFloor Construction, of

is a specification.

My invention re ates in. eneral to floor construction and more specically to a voidforming core adapted to materially diminish the weight ofconcrete and plaster iloorswithbut alfecting the strength of the floor.'The present application is a division of m eopending application SerialN o. 20,162, filed A 1419,1915.

n order'to meet the requirements of a thoroughly satisfactoryvoid-producing core for use in floor construction the core must light inweight, stron and substantial, ca'- able of being manu actured inrelatively ar sizes, uniform in size and shape, capab e of being easilyand water-proof and non-conductive of sound.

Itis the object of my invention to produce a core which meets all of theabove requirements and which is in every way superior to the devicesheretofore in use for this pur- POSin the art.

Another further to produce concrete lioors` constructionthan hasheretofore been ossisaving in material being efipected by thecomparatively light weight of the cores employed.

Further objects and advantages of my in# a parent as it is betterunderstood by lrefirence to the followin slpecification when t eaccompanying drawing in which- Figure 1 is a perspective view of a comtobe placed 'in position; ig. 2 is a vertical section of a floor showingthe cores disposed side by side and the manner of applyung the lceilingplaster; and

Fig. 3 is a vertical -section through a sheet of plaster board of thetype which I preferably employ in carrying out my invention.V Referringto the drawin 1 indicates generally a core of laster ard' providedobject of my invention is of much lighter formin adapte to space thecores laterally when verized hardened plaster fitted into position, fireread in connection wit i 3, having flanges 4. supporting feet for thecore and placed side by side as indicated in Fig. 2. The bottom 5,consisting of a sin le sheet of plaster board is secured to the iiganges4 by means of clips 6 of which any suitable number may be employed. Theclips are refer# ably of soft iron, easily bent in any esired direction.and are provided with upwardly extending tongues 7 adapted to beembedded in the concrete as indicated in Fig. 2.

The method of makin the cores is as follows: The plaster-ofaris, mixedwith )vater to the proper consistency and containing'Z if desired, acertain proportion of pulwhich acts as an accelerator for the settingoperation, is disposed between opposite sheets of a reinforcingmaterial, preferably a wool felt, and the mass is subjected to pressurewhereby the plaster is forced finto the interstices of the felt andbecomes incorporated therewith to Patented Mar. 13,1917.`

or otherwise coated with afsuitable water,-

proofing material, such as pitch. The waterproofing material impregnatesthe surfaces of the molded core and not only waterproofs the structurebut strengthens it to a considerable extent so that it is better able y-A to withstand rough usage inV shipment and the handling` -necessaryduring building operations. he molded portion of the core is assembledwith the bottom sheets 5 and secured thereto by clips 6 at the job.l Thebottom sheets 5 may be water-proofed if desired. y

I have described my method in its simlest formand iii connectionwith aplaster oard consistin of a layer of plaster covered on either side by asheet of reinforcing material. If desired the plaster board may be Vmadeas in Fig..3 and consisting of a plurality of layers-of Y laster 16 andreinforcing material 17. e resulting plaster board is molded to form thecores exactly as in the receding description.

Prefer-a ly the pressure to which the mass able rolls so that los lwhich continuous. In carrying out the meth'od the cores may-be molded ina continuous sheet of plaster board andy se arated after the plaster ishardened or, i -desired, the plaster board may be cut into desiredlengths while the plaster -is still in the plastic condition andsubsequently molded before the plaster hardens. In either case thewater-proofing step will follow the drying operation after which thecores, which are out to uniform and standard sizes, are readyforshipment.

In the use of my invention a suitable false-work is erected which needcomprise only beamsspaced at intervals equal to the width of the coresland the cores with their bottoms secured in place by means of the clips6 are mounted lin rows on the beams, end to end, and with the flanges 4of adjacent rows engaging, as indicated in Fig. 2. Preferably theindividual cores of adjacent rows are disposed in staggered relation sothat the joints between the cores in the adjacent rows are not in thesame line. When all of the cores are in place the reinforcing members 8are placed in position and the concrete 9 is poured and allowed toharden.

vThe concrete enters the spaces between the 'adjacent rows of cores'andforms beam sections which, with the reinforcing members, support theload of the floor. The ceiling plaster 10 is applied directly to thebottom sheets 5 of the cores and owing to the nature of the reinforcingmaterial the ceiling plaster forms avstrong bond with the sheets 5 whichhold the plaster in position indefinitely.

Plaster board is comparatively light in weight and a saving ofapproximately twenty-five pounds per square foot in the Weight of thecores alone is possible where plaster board cores are substituted forthe clay tile of the prior art. A further saving is. ell'ected in theamount of concrete and steel necessary to sustain. the dead-load of theloor and both ofthese savings are transferred in turn to the supportingcolumns may be correspondingly lighter. Cores of plaster board are alsolighter than the cores of solid plaster, concrete or sheet metal of theprior art.

Cores of plaster board are strong and substantial, `u-ithstai'idingrough usage in shipment and setting, and are preferable to clay tilecores which are exceedingly britvtle and sheet metal cores which. areeasily dented and deformed when repeatedly handled by careless workmen.Solid plaster cores are too fragile `for commercial use and cement coresare obviously too heavy for economica-l shipment.

Plaster board cores may be made in relatively large sizes o'f uniformshape and size, whereas claytile cores are limited in size owing todiliculty of firing. Clay tile cores are, even in the smaller sizes,always more or less warped and are, therefore, not uniform in shape.Sheet metal cores are' so deformed by handling that they are rarely ofuniform shape when they reach the job. By the use of laster board coreslonger spans are possible anda larger amount of space is therebypossible in a building of given size. The uniform shape of plaster boardcores allows them to be more readily placed in position and inasmuch asthe plaster board may be neatly cut and trimmed by means of ordinarycarpenters tools'a considerable saving in labor is effected by the useof these cores rather thanthose of the prior art which are cut withdifiiculty and are frequently spoiled during the cutting operation.

Plaster board is extremely resistant to fire and it will be readilyunderstood from the foregoing description and by reference to thedrawing, particularly Fig. 2, that by the use of my invention theunder-side of the concrete is protected from fire by two layers ofplaster board and in addition a large part of the under surface isfurther protected by the dead air space Within the cores. Furthermoreshould all or portions of the ceiling plaster be damaged, by fire forexample, and the bottom sheets 5 thereunder be injured, the ceiling maybe easily replaced or repaired by bending the clips and removing andreplacing the lnjured sheets with newI sheets after which ceilingplaster can be applied to the new sheets as before. be done without-injury to the cores or floor structure and without necessitating theVreplacement of any other parts than the bottom sheets, thereby greatlyreducing the cost of replacing or repairingthe ceiling.

By the sse of cores having plaster board bottoms to which the ceilingplaster may be directly applied a material saving in the cost ofplastering is effected. Wire lath has been universally used with metaldomes as a -110 base to which the ceiling plaster is applied. Thismaterial invariably sags and a greater thickness of plaster rounds isrequired not only to securely bono? the plaster to the'wire .lath butalso to obtain a Hat ceiling, it being 115 obvious that the distanceofthe wire lath surface from the lower sur-face of the Hoor greater atthe center of the span than at its ends owing to the sag of the wirelath. When clay tile are used the ceiling surface is 120 uneven andirregular and an excessive amount of .plaster must be used to obtainuniform grounds. Plaster board not only bonds with the ceiling plasterwithout the necessity of providing openings into which 125 the plasteris forced as in wire lath and clay tile practice but also provides aflat surface throughoutthe span so that the thickness of the plastergrounds doesnot vary. The ceil- This Call plaster board than `to Wirelath nsince the plaster board presents a firm surface to the plasterer,whereas the wire lath moves up and down at each application of theplasterer`s tools.

The continuous ceiling surface eliminates the alternatelight anddark-lines caused by the depositingof dust in the air currents whichpass through the clay tile and not through the denser concrete. Alsorust stains from the metal lath are eliminated. (,vlay tile containsoxide. salts, etc., which work out to the surface of the plaster causingellorescence and stains.

It is obvious that various changesmay be made in the form, constructionand arrangement of the parts Without departing from the spirit and scopeof the invention or.- sacrificing any of its material advantages, theform hereinbefore described being merely preferred embodiments thereof.

I claim:

l. A core for concrete and plaster conhaving a top and outwarc ly Haringintegral sides of a width equivalent to the desired depth of said core,the lower edges ot' said sides projecting outwardly parallel to said topand forming flanges,a bottom consisting of a flat sheet of plasterboard, and metal clips securing said bottom to said flanges.

CHARLES F. HENNING.

1Witnesses:

WM. O. BELT,4 M. A. KIDDIE.

